1. Field of the Invention
This invention relates generally to an interior bag for implantation in the natural capsular bag of an eye and an injector therefor and, more particularly, to an apparatus and method for preventing the condition of posterior capsular opacification (PCO), a condition occurring in about 25 percent of cataract surgery patients, and for preventing and/or treating other conditions of the eye.
2. Background Information
A cataract is a clouding of the lens of the eye, the lens being responsible for focusing and producing sharp images. Cataracts are the leading cause of vision loss among adults 55 and older. Eye injuries, diseases, and certain medications are believed to accelerate the formation of cataracts.
The lens is contained inside the natural capsular bag in a human eye. Alteration of the structure of the lens over time causes lens opacification or clouding, which makes images look blurred or fuzzy. This process is a natural result of aging and can be accelerated due to injury, disease or medication.
PCO can occur after cataract surgery and cause patients to experience symptoms similar to those from the original cataract. During cataract surgery, a patient's natural lens is replaced with a small artificial lens, called an intraocular lens or IOL. Unfortunately, proteins and/or cells, such as lens epithelial cells retained in the capsular bag following surgery, may proliferate and migrate to the posterior surface inside the capsular bag causing PCO, thereby making clarity of vision difficult.
In an effort to treat PCO patients, surgeons have focused on methods of treating the cells on the inside of the capsular bag. Methods used in the past have included lysing, freezing, polishing, and laser treatment. Unfortunately, some of these methods carry a higher risk of developing a retinal detachment in the future. Additionally, some of these methods may also cause the intraocular lens to dislocate and necessitate surgical repositioning and, in unfortunate cases, result in the destruction of the capsular bag. Moreover, each of these methods does not adequately limit future cell formation inside the capsular bag because aqueous humor fluid flow through the capsular bag continues to provide an environment friendly to cell growth or even cell migration into the posterior part of the bag via fluid flow causing PCO. There is a need in the art to provide a means for inhibiting PCO.
There is also a need to provide a means for retaining the shape of the capsular bag and for reducing or eliminating shrinkage of the capsular bag following cataract surgery. In addition, experiments are now underway to inject silicone or other transparent materials into the capsular bag following cataract surgery to form a replacement lens in situ rather than using a conventional IOL and the present invention may facilitate the use of such a lens. The present invention may further provide a reservoir for retaining and releasing a time release pharmaceutical agent for treatment of glaucoma or infection such as iritis or uvitis.